The present invention relates to rotating electric machines and comprises primarily a process for the production thereof and especially a new method for the production of the stator and equipment connected to it.
Electric motors have normally a stator with the laminations arranged perpendicular to the rotor axis, and with windings arranged substantially parallel to this axis. The laminations are held together in a package by means of bolts or the like. The stator with connected rotor is usually mounted in a housing or a case of aluminum or other suitable material.
The stator of an electric motor may also have its laminations arranged parallel to the rotor axis. The edges of the laminations along the rotor axis are then bent inwards towards the rotor axis for the guidance of the magnetic flux. The windings may then be arranged around the bent edges or around the middle part of the lamination package. Such motors may be induction motors, commutator motors and permanent magnet motors.
When electric motors are manufactured it is usual that the stator and the rotor are prepared separately in a nearly finished state, whereafter the rotor is mounted with its bearings in the stator. It is then necessary to insert the rotor into the stator cavity from one end and thereafter secure it in its bearings in a convenient way. In conventional assembly methods, any elements such as tools of various kinds carried by the rotor shaft must be assembled to the rotor shaft after the final mounting of the rotor in the stator. For example, the diffuser and the fan wheels in a vacuum cleaner, must therefore be attached stepwise after mounting the rotor. Such a method may lead to sufficient products, but is both complicated and expensive, especially through the time-consuming mounting of the stator windings and of the many small parts which in proper order must be put into the machine from one end.